Open AccessThe evolution of brain neuron numbers in amniotes
Author(s) -
Kristina Kverková,
Lucie Marhounová,
Alexandra Polonyiová,
Martin Kocourek,
Yicheng Zhang,
Seweryn Olkowicz,
Barbora Straková,
Zuzana Pavelková,
Roman Vodička,
Daniel Frynta,
Pavel Němec
Publication year - 2022
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.2121624119
Subject(s) - brain size , biology , cerebrum , neuron , neuroscience , evolutionary biology , phylogenetic tree , phylogenetics , biological evolution , central nervous system , gene , genetics , medicine , magnetic resonance imaging , radiology
Significance The evolution of brain processing capacity has traditionally been inferred from data on brain size. However, similarly sized brains of distantly related species can differ in the number and distribution of neurons, their basic computational units. Therefore, a finer-grained approach is needed to reveal the evolutionary paths to increased cognitive capacity. Using a new, comprehensive dataset, we analyzed brain cellular composition across amniotes. Compared to reptiles, mammals and birds have dramatically increased neuron numbers in the telencephalon and cerebellum, which are brain parts associated with higher cognition. Astoundingly, a phylogenetic analysis suggests that as few as four major changes in neuron–brain scaling in over 300 million years of evolution pave the way to intelligence in endothermic land vertebrates.